Foxa3 is a transcription factor that is thought to act as a 'pioneer' factor opening the compacted chromatin for other proteins through interactions with nucleosomal core histones and thereby replacing linker histones at target enhancer and/or promoter sites. Foxa3 is originally described as a transcription activator for a number of liver genes such as AFP, albumin, tyrosine aminotransferase, PEPCK, etc. Foxa3 interacts with the cis-acting regulatory regions of these genes.Foxa3 is involved in glucose homeostasis; activates GLUT2 transcription and regulation of neuronal-specific transcription. Foxa3 is also involved in regulation of spermatogenesis; required for the maintenance of the testicular germ cell population and male fertility.